There are many websites nowadays that allow user postings either to sell products, make comments, provide reviews or for a number of other reasons. However, when other users review these postings, it is difficult to determine if the poster is trustworthy. Furthermore, the poster might even be a close friend, but if the user is unaware that the friend goes by a certain user name, the user will view that poster as simply another random poster.
For example, if a user comments on a movie review website and rates the movie a “D”, that may be some help to other users, but maybe the person simply does not like a specific actor in the movie or some other aspect that is not highly relevant in other users' decisions about the quality of the movie. However, usually friends have similar tastes in movies and therefore it would be helpful to know that the review is someone the user knows. Since users tend to have different usernames for different sites, it is not necessarily simple to just remember usernames for each of a person's acquaintances since people are able to use different user names for each website and there are a plethora of websites available online.